An agricultural harvester, such as a combine, is a large machine used to harvest a variety of crops from a field. A combine includes a header at the front of the combine to cut the ripened crop from the field. A feeder housing supporting the header transfers the crop material into the combine for threshing. The threshing and separating assemblies within the combine remove grain from the crop material and transfer the clean grain to a grain tank for temporary holding. Crop material other than grain exits from the rear of the combine and is distributed upon the field. An unloading auger or conveyor transfers the clean grain from the grain tank to a truck or grain cart for transport.
U.S. Pat. No. 6,216,071 discloses an apparatus and method for coordinating and monitoring the harvesting and transporting operations of an agricultural crop by multiple agricultural machines in a field. A grain cart is scheduled to be available for the unloading of harvesting machines when the harvested crop reaches a predetermined level in a particular harvesting machine. In US Patent Application Publication No. US 2006/0014489, there is disclosed a drive support system that coordinates the harvesting machines in a field and generates driving routes that are coordinated with each other so that the agricultural machines avoid collisions therebetween particularly during unloading procedures when the grain is transferred to a trailer. Canadian Patent CA 2 305 606 discloses an arrangement in which a vehicle is controlled from the first vehicle to maintain a set working position alongside the first vehicle utilizing GPS or ultrasonic distance measuring equipment. The second vehicle can be a loading truck for receiving discharge from a crop harvesting machine. German Patent Document DE1 0064862 discloses a system of coordinating agricultural vehicles working in the same field and between which crop is transferred including a navigation system fitted on one of the vehicles having a system for transmitting data between the vehicles.
What is needed in the art is a method and apparatus for coordinating the transfer of grain from multiple harvesters in a simultaneous manner.